Continuous casting



June 1956 M. LOEWENSTEIN 2,749,583

commuous CASTING Filed April 16, 1952 2 Sheets-Sheet l AV E 2 4. SWITCHVALVE.

la la b IN V EN TOR.

flax L aewensze z'rz June 1956 M. LOEWENSTEIN CONTINUOUS CASTING FiledApril 16, 1952 2 Sheets-Sheet 2 n I I r [III Illllllllllllllllllllll HII 57 I I II m I I 1 I 6| 4 62 m III 54 4 nism of the runner box 21 areso arranged that the nozzle 30 of said extension 32 will in allpositions of the metal level A within the passage 14 project downwardlybelow said level A, and preferably project below said level for for acertain distance 11. This is accomplished by moving the runner box 21along substantially in synchronisrn with the movement of the metal levelA within the passage 14. For instance, when the metal level A is low,the runner box 21 and the extension 32 will be in its lower position(shown in solid lines in Fig. 1), and conversely, when the metal level Ais near the top of the passage 14, the runner box 21 and the extension32 will be in the upper position (shown in broken lines in Fig. 1).

There is provided a mechanism, generally indicated at 36 which isoperable to reciprocate the runner box 21 axially of the mold 11, insuch a manner that the tube 32 will always be in axial registry with thepassage 14. That reciprocating mechanism 36 comprises a plurality of,for instance two connecting rods 37 and 38, that are connected to therunner box 21 at a flange 39 thereof and which are reciprocably slidablein bearing structures 41 and 42, respectively, that are secured to thebase 13.

The lower ends of the connecting rods 37 and 38 are connected to thecasting withdrawing mechanism, and the latter will now be describedbefore completing the explanation of the working of the reciprocatingmechanism 36 for the runner box 21.

The casting withdrawing mechanism is generally indicated at 43, and isdisposed below the bottom opening 17 of the mold 11. Said mechanism 43comprises a plurality, for instance two pairs, of oppositely arrangedflanged rollers commonly known in the trade as pinch rollers.

The rollers of each pair are in superposition, the pair at the left sideof the apparatus having a lower roller 44 and an upper roller 46, whilethe pair on the right side has a lower roller 57 and an upper roller 48.The righthand side pair of rollers 47 and 48 is carried by a doubleconnecting lever 49. Two springs 53 are provided, one acting on eachhalf of the double lever 49, to control the position of the rollers 47and 48 to follow the change of the contour of the casting. The doubleconnecting lever 49 has a top half portion 49a and a bottom half portion49b, and both portions are tiltable about the axis of the shaft 51. Theshaft 51 is immovable. As the portions 49a and 49b of the doubleconnecting lever 49 carry the rollers 48 and 47, respectively, theserollers under the action of the springs 53 will move arcuately about theaxis of the shaft 51 following the change of the contour of the casting.The shaft 51 is disposed in a horizontal guide 52.

The left side pair of rollers 44 and 46 is provided with brackets 50.One of the pair of rollers, for instance the right hand pair of rollers47 and 48, may be adjustable manually, as shown with the spring loadedspindle and crank arrangement 53. The upper rollers 46 and 48 areopposite each other, and likewise the lower rollers 44 and 47 are alsoin opposite arrangement, to pinch therebetween the casting 54 emergingfrom the mold passage 14. Each of the rollers carries a gear, the roller44 having a gear 56, the roller 46 a gear 57, the roller 47 having agear 58 and the roller 48 a gear 59. Between the gears of each rollerpair, there is a pinion, the left hand pair having a pinion 61, which isjournalled on the shaft 62 and meshes with the gears 56 and 57, and theright hand pair having a pinion 63 that is journalled on the shaft 51and meshes with the gears 58 and 59.

The shaft 62 carries also a gear 64 keyed thereon for tied rotation withthe pinion 61, and the shaft 51 carries similarly a gear 66 that rotateswith the pinion 63. The gears 64 and 66 are in mesh, so that therotation of the pinion 61 is thus transmitted to the pinion 63 by way ofthe shafts 62 and 51 thereof and of the gears 64 and 66. When the leftpinion 61 is rotated in the direction of an arrow 67 (counterclockwise),the gears 56 and 57 will rotate clockwise (arrows 68), thereby rotatingthe rollers 44 and 46 in that direction 68. At the same time, the gear64 will be rotated in direction 67 by the pinion 61 and will turn thegear 66 in direction 68, thereby turning in that clockwise direction thepinion 63. The pinion 63 will turn the gears 58 and 59 counterclockwise(direction 67), thereby rotating the right hand rollers 48 and 49 inopposite directions as compared to the left hand rollers 44 and 46, inorder to pull downwardly the casting 54 therebetween.

The rollers 44, 46, 47 and 48 all have the same diameter. Furthermore,the pinion 61 has the same diameter as the pinion 63. The gears 56, 57,58 and 59 have all the same diameter; and the gear 64 has the samediameter as the gear 66. Thus, all the rollers 44, 46, 47 and 48 willhave the same circumferential speed, at use.

It will be understood that the terms left and right" and clockwise andcounterclockwise are used only for clarification, and simplification ofthe description, but that no limitation is thereby intended.

There is provided an actuator 69, designed to rotate in oppositedirections the pinion 61. The actuator 69 comprises a hydraulic cylinder71 that is pivotally mounted at 72 and has a piston 73 to which there isattached a connecting rod 74, of adjustable length, which carries apivot 76. A lever 77 connects the said shaft 62 with the pivot 76, tocarry out the rotation of the shaft 62 and thereby of the pinion 61.

Lowering of the piston 73 in the cylinder 71 will turn the lever 77 fora certain angle, causing rotation of all the rollers for moving thebillet 54 downwardly for a predetermined distance 0. The circumferenceof the rollers and the length of stroke of the piston 73 are sodimensioned that one downward stroke of the piston 73 will causewithdrawal of the billet 54 for a distance which corresponds to thedistance 0 between the uppermost position 78 of the molten metal level Aand the lowermost position 79 thereof.

Following the downward stroke of the piston 73, there occurs a slowupward return stroke thereof, commencing immediately following thedownward stroke, after which there will follow the next downward strokefor withdrawal of the casting 54.

There is provided a suitable unidirectional free wheeling device ofconventional design (to control the power transmission), for instance anoverrunning roller clutch, between the pinion 61 and the rollers 44 and46 of its gears 56 and 57, and a similar device to control the powertransmission between the pinion 63 and the rollers 47 and 48 of itsgears 58 and 59, so that the rollers will only be rotated during thedownward stroke of the piston 73, and will remain at standstill duringthe upward stroke thereof. A free wheeling device of the type referredto is illustrated in Fig. 4 operating between the gear 57 and the roller46 thereof. Balls B are disposed in wedge shaped 1 chambers formedbetween surfaces C and D of the gear 57 and the roller 46,respectively.v Thus, when the gear 57 is turned by the gear 61 in thedirection 68, the balls B will be in wedging engagement with the gears57 and the roller 46, and the gear 57 will turn the roller 46 in thesame direction 68; when the gear 57 is turned in the Opposite direction67, however, the balls B will be in the inactive position shown in Fig.4, wherein no wedging takes place, and the roller 46 will not partake inthe rotation in the direction 67.

As the piston 73 moves down and up, the billet 54 will be withdrawnintermittently, in a step-by-step motion, so that periods of withdrawalalternate with intervals of standstill.

During these standstill intervals, the molten metal owing to itscontinued discharge from the tube 32, will refill the passage 14 untilthe metal level A has reached the-upper position 78. :Nearthatpositionof thellevel, there will be actuated an actuatiugmeanstooperate the-cyli;nder' 71-;toretract: the I piston ,72 downwardly.

'Iihatactuatingmeans is shownpschematically in Fig. 1 iand designated81. it comprises an ,electric circuit which is interconnected to anelectric source, as schematically illustrated by an electric plug 82.The circuit .includes :twoterminals 83that are spaced from :each otherand \disposed on the interior of they passage :14 and insulated 1atl8'4from the metalof the-mold 1 1. The terminals 83 :arepreferablymade of amaterialthat is conductive and -at the same time .has .a melting pointsufiiciently high above-the temperature of the molten metahso that .whenthe molten metal level A rises to the terminals 83.it will bridge thesame electrically but-without melting them. The terminals 83 areinterconnected to a relay and switch mechanism86, which in'turn actuatesa valve operator 87 to control the flow ofhydraulic ilui'd in thecylinder 71, and also actuates a signalling device suchas a signal lamp88 to indicate to-the operatorthat the molten metal level A hasreachedthe upper position 78. Following the completion of the-electriccircuit by the bridging of the'terminals 83, the actuator 69 will causewithdrawal of the'bil-let54 substantially for a distance corresponding-tothe distance 0 between the upper level position 78 and the lowerlevel position 79. Thereafter, while the billet 54 is at a standsitll,the molten metal will again fill up to the upper level 78 forsubsequently starting another withdrawal operation.

One or both of the rods.37.and.,3 8, may beprovided on the lower endwith a rack 91 and 92 respectively, that is engaged in'mesh' with thepinions-61=and 63 adjacent thereto. Consequently, when the piston 73 islowered, the:p,inion.61 which is turned thereby will rotate in adirection 67, and the pinion 63 will turn in the opposite :direction68;the pinions61 and 63 thereby will lower the rods 37 and 38 owing totheengagement .with the-rack 9,1 and 92 on the outside ofthe pinions 61 and63, respec- .ti-v'ely. As a result, 1owering of .thecasting 54 will takeplace in synchronism with the lowering of the runner box 21. During theupward return stroke of the piston 73, the pinions 61 and 6-3 will bereversed while, due to the free wheeling connection between the pinions61 and 63 on the one hand and the, rollers 44, 46, 47 and 48 on theother hand, the rollers will remain at a standstillsduring the saidreverse rotation of the pinions 61 and 63, the engagement thereof withthe racks 91 and 92 will cause an upward movement of the rods '37 and 38and consequently of the runner box 21., Thus, While the billet 54 is ata standstill, the runner box 21 will be lifted into the upper position78.

This lifting of the runner box 21 is so arranged, by means of adjustmentof the movement of the piston 73 that the speed of lifting of the runnerbox 21 will substantially be in synchronism with the raising of thelevel A in the passage 14, as the filling of the mold 11 proceeds duringthe period of standstill of the casting 54.

This lifting movement of the runner box 21 is brought to an end by thetermination of the upward stroke of the piston 73. The piston 73 willagain be lowered after it is actuated when the molten metal has filledup the mold until the level A thereof bridges the terminals 83.

The linking of the pinions 61 and 63 with the rollers 44, 46, 47 and 48on the one hand, and with the racks 91 and 92 on the other, causes asimultaneous downward movement of the billet and of the rubber box, atthe same speed and to the same extent. The distance A between theextreme positions of the runner box 21, accordingly is equal to thedistance c between the extreme positions of the metal level A, whichalso corresponds to the billet Withdrawal length during one cycle.

As best shown in Fig. 1, the distance between the bottom of the mold 11and the upper rollers 46 and 48 is small, so that only a short dummyingot is needed to f6 Liclose .Lthe ;bottom of the ,mold rat the start.of spera- -tion, :and ;this dummy ingot can {be readily moved 31p-:wardly between the jfeed rollers. {Forthis purpose, free wheeling:device referred to :in theferegoing maybe made releasable, so that thepiston 73 during,its upward :stroke may move-the dumrnyingot "intoposition.

With this intermittent withdrawal method, billets .may becast'o'falength limited only by thespace available below the apparatusand by the capacity of the furnace 26. However, in :most instances, litwill --be.desired to cut the billet intosizes of predetermined length,for easier handling and transportation. The cutting may best be carriedout during the standstill intervals ofthe billet. *Fortliis-purpose,thereis provided a. cutting arrangement generally indicated at 93 whichcomprises .a cutter 94, .21 power motor 96 to rotate the cutter, andhydraulic-means to feed the cutter transverse of the billet for severingthe same. The motormay run continuously ot-periodically during thecutting operation. Leads 99 connect-themotor 96 to the actuating means81 for the interconnection to an electric source. A hydraulic cylinder95 andpiston are-provided to advancethe cutter -94-in-an operationdirection97 and'the piston movement is synchronized with the castingstandstill periods. During movement-in the direction 9 7,-the cutter 94will cut the castings 54.

The entire cycle of movement, first in the operating directions '97, andthen in the idling direction 98,-must be completed during the standstillperiod of the casting'54.

. Means are provided to lubricate the surface of the casting passagei1'4in the mold 11. For inst ance,'a conduit is provided in the runner box2l that has spray outlets at a point slightly above the point immersionof the extension ;32 below the rnetallevel A. As the extension 32 issubstantially synchronized in its movement with the movement ofsaidlevel 'A,'the spray;outlets 95 will at alltimes remain above the'level A and can cover that part of the passage 14 thatis free of moltenmetal with a fine film for'lubricating the inner wall of the mold '11. v

In accordance with the invention, an elastic fluid agent such as aninertgas, can be introduced under pressure into thatspace of'the passage14 formed abovethe metal level A,'in order to prevent oxydation. Thegasmaybe introduced for instance through a sealable channel 101, that isformed in therunner' box 21.

Where billets are being cut to a desiredlength by meansof the cuttingarrangement 93, the cuttingas explained 'in the foregoing will take.place duringbillet standstill intervals. However, the 'cutofilength.,does not'have'to be the same as the length of drop of the billetduring each withdrawal thereof but instead may be a multiple of thatdrop length. In order to accomplish this automatically, the actuatingmeans 81 may be provided with a timing or counting device of well-knownconventional design to actuate the cylinder 95 only after apredetermined number of Withdrawal cycles.

Billet sections which have been cut by the cutter 94 may be dischargedinto a vessel, such as a basket 102 that is movable to and from avertical receiving position in registry with the billet casting positionand shown in solid lines in Fig. 1. The basket 102 may be tilted into aposition away from the said receiving position into a discharge positionshown in broken lines at 102, so that the billet section 54 may bedischarged therefrom onto rollers 103.

In order to carry out the tilting of the basket 102, there is provided atilting mechanism generally indicated at 104 which comprises a hydrauliccylinder 106 that operates a piston 107 which is linked by links 108 tothe basket 102. The basket furthermore carries on one side a rack 109that engages a freely turnable pinion 111 for positioning the basket 102in tilted position 102'.

When the cutter 94 is not used, and the billet 54 is cast in fulllength, it may be discharged onto a rotor, such as a rotating table 112shown in Fig. 3. By a rotation of the table 112, the billet 54 may bemoved into a position 54' away from the casting position, so that it canbe picked up by an overhead hoist. Receiving baskets (not shown) may bemounted on the table 112 to receive billets 54 discharged from the mold11, and while one billet is being hoisted from the position 54', anotherbillet meanwhile may be cast and discharged onto the table 112.

It will be apparent to those skilled in the art that the novelprinciples of the invention disclosed herein in connection with specificexemplifications thereof will suggest various other modifications andapplications of the same. It is accordingly desired that in constructingthe breadth of the appended claims, they shall not be limited to thespecific exemplifications of the invention described here Having thusdescribed the invention, what I claim as new and desire to be secured byLetters Patent, is as follows:

1. In a casting machine having a stationary mold forming a substantiallyvertical casting passage open on top and bottom and arranged to receivemolten metal of varying level and means for intermittently actuatingwithdrawal of casting from the bottom opening, in combination, means fordelivering molten metal through said top opening into said passage,comprising a reservoir structure reciprocably disposed above saidpassage and arranged to hold and to discharge molten metal, a tubularextension projecting downwardly from said structure andintercommunicating interiorly with said reservoir and extending intosaid passage for discharging from said reservoir molten metal into saidpassage, and means connected to said actuating means and to saidreservoir structure forcibly lowering the latter during, and insynchronism with, the casting withdrawal and, respectively, raising thesame during casting standstill.

2. In a billet casting machine, as claimed in claim 1, furthercharacterized in that, the movement of said reservoir structure beingsubstantially in synchronism with the movement of the metal level in themold.

3. In a casting machine having a stationary mold forming a substantiallyvertical casting passage open on top and bottom, and a mechanism forintermittent casting withdrawal, in combination with, means fordelivering molten metal into said passage through said open top andcomprising a reservoir structure vertically reciprocably disposed abovesaid passage for receiving and for discharging molten metal, a nozzlemovable with said reservoir and intercommunicating therewith andextending into said passage below the metal level therein fordischarging molten metal thereinto from said reservoir, and meansconnected to said withdrawal mechanism and to said nozzle and operableto move said nozzle in synchronism with said casting during withdrawalfor maintaining said nozzle during withdrawal below said level.

4. Delivery means for molten metal, for use in connection with a castingmachine having a stationary mold forming a substantially verticalcasting passage and means for Withdrawing casting in solidified formintermittently from the bottom thereof, said delivery means comprising atube interconnected to a source of molten metal and extending into saidpassage for delivering molten metal to the interior thereof and beingreciprocably movable in registry with said passage, the lower end ofsaid tube projecting into the molten metal disposed in said passagebelow the upper level thereof throughout the changes in verticalposition thereof, and means connected to said withdrawing means and tosaid tube and operable for maintaining said lower end substantiallyspaced for the same distance below said upper metal level in saidpassage throughout the withdrawal periods of said metal.

5. Delivery means, as claimed in claim 4, together with, said last namedmeans including means for synchronizing the movement of said tube withthe movement of said metal level comprising a mechanism between saiddelivering means and said casting withdrawing means and actuated by thelatter and operable to control the reciprocable movement of said tube.

References Cited in the file of this patent UNITED STATES PATENTS394,695 Illingworth Dec. 18, 1888 1,139,888 Mellen May 18, 19151,666,910 Poske Apr. 24, 1928 1,983,579 Ennor et al. Dec. 11, 19342,290,083 Webster July 14, 1942 2,455,433 Matson et a1. Dec. 7, 19482,582,329 Harter et al. Jan. 15, 1952 FOREIGN PATENTS 598,385 GreatBritain Feb. 17, 1948 925,131 France Mar. 24, 1947 OTHER REFERENCES PB L83878, German patent applications on foundry work (FIAT Microfilm Reel 195"), Frames 7099 to 7109, inclusive. Offered for sale on page 1016 ofBibliography of Scientific and Industrial Reports, Ofiice of TechnicalServices, U. S, Department of Commerce, vol. 9, No. 11, June 11, 1948.

1. IN A CASTING MACHINE HAVING A STATIONARY MOLD FORMING A SUBSTANTIALLYVERTICAL CASTING PASSAGE OPEN ON TOP AND BOTTOM AND ARRANGED TO RECEIVEMOLTEN METAL OF VARYING LEVEL AND MEANS FOR INTERMITTENTLY ACTUATINGWITHDRAWAL OF CASTING FROM THE BOTTOM OPENING, IN COMBINATION, MEANS FORDELIVERING MOLTEN METAL THROUGH SAID TOP OPENING INTO SAID PASSAGE,COMPRISING A RESERVOIR STRUCTURE RECIPROCABLY DISPOSED ABOVE SAIDPASSAGE AND ARRANGED TO HOLD AND TO DISCHARGE MOLTEN METAL, A TUBULAREXTENSION PROJECTING DOWNWARDLY FROM SAID STRUCTURE ANDINTERCOMMUNICATING INTERIORLY WITH SAID RESERVOIR